PETS-5教材.pdfVIP

波波 mp3 学习资源网 () 全国公共英语等级考试 教程第五级 Script for Listening Comprehension Unit 1 Finding It Online One of the great features of the Internet is the amount of information it contains. Information that used to be limited to regional distribution via newspapers and televisions is now available around the globe. You can look for a job in a faraway city or country. You can sell your coin collection via a national classified ad. You can look up a phone number for a restaurant in Paris. But all this newly available information comes at a price: confusion. The interconnected and dynamic nature of the Net prevents it from being organized like a traditional medium, such as a book or a newspaper. But dont worry, another great thing about the Internet is that it comes up with solutions for its own problems. Enter Internet Guides and Search Engines... If the Internet were a book, Internet Guides would be the table of contents. They organize web sites into related categories or topics, just as a table of contents organizes the chapters in a book into different sections. Of course, in the case of the Internet, the book is so big that even the table of contents needs its own table of contents. Thats why most Internet Guides start with top-level categories and let you drill down to more and more specific topics. If the Internet were a book Search Engines would be the index. In order to combat the dynamic nature of the Web, Search Engines are constantly running software called robots or crawlers that read entire web sites and update the index entries for that specific Search Engine. Search Engines save their data alphabetically, just like a books index. But, again, due to the incredible amount of information, you dont browse through a Search Engines listings, you search through them by entering